Method for manufacturing false twisted threads from thermoplastic resin tapes

ABSTRACT

A method for manufacturing false twisted thermoplastic thread from thermoplastic resin tape comprises passing the tape through a region wherein an eddy stream of a high temperature high pressure fluid such as steam, superheated steam and air is present. The eddy stream is produced by eccentrically jetting a high pressure fluid of a temperature not lower than the plasticizing point having the thermoplastic resin tape into a cylindrical thread forming tube. The thermoplastic resin tape is false twisted so as to form a cylindrical bundled thread and simultaneously thermoset in the bundled form all by the effect of the eddy stream.

United States Patent Kosaka et al.

[451 Nov. 7, 1972 [73] Assignee: Mitsubishi Rayon Company Limited,

Tokyo, Japan [22] Filed: Aug. 4, 1969 [21] Appl. No.: 847,132

[30] Foreign Application Priority Data Aug. 14,1968 1 Japan ..43/57477[5 6] References Cited UNITED STATES PATENTS 2,900,782 8/1959 7Bobkowicz ..57/155 X 3,206,922 9/1965 Nakahara et al. ..57/77.3

Breen et al. ..57/157 3,303,639 2/1967 Carter et al ..57/77.3 3,371,4773/1968 Felix ..57/157 F 3,378,997 4/1968 Matsui et al. ..57/34 3,398,2208/1968 Port et al. ..57/167 X 3,398,441 8/1968 Adachi et al...'.....28/72 3,422,616 1/1969 Felix ..57/157 3,444,683 5/1969Hessenbruch ..57/157 3,470,685 10/1969 Hall et al. ..57/140 3,473,20610/1969 Boultinghouse ..28/72 3,474,611 10/1969 Suzuki et al. ..57/313,488,941 1/1970 Asaka ..57/157 Primary Examiner-John PetrakesAttorneyRobert E. Burns and Emmanuel J. Lobato [5 7] ABSTRACT A methodfor manufacturing false twisted thermoplastic thread from thermoplasticresin tape comprises passing the tape through a region wherein an eddystream of a high temperature high pressure fluid such as steam,superheated steam and air is present. The eddy stream is produced byeccentrically jetting a high pressure fluid of a temperature not lowerthan the plasticizing point having the thermoplastic resin tape into acylindrical thread forming tube. The thermoplastic resin tape is falsetwisted so as to form a cylindrical bundled thread and simultaneouslythermoset in the bundled form all by the effect of the eddy stream.

25 Claims, 17 Drawing Figures PATENTED I!" 7 I972 SHEET 1 OF 3 PATENTEDIIUV 7 I972 SHEET 2 BF 3 METHOD FOR MANUFACTURING FALSE TWISTED THREADSFROM THERMOPLASTIC RESIN TAPES The present invention relates to a methodfor manufacturing false twisted threads from thermoplastic resin tapes,and more particularly relates to a method for manufacturing falsetwisted threads which are thermoset by an eddy stream of a high pressurefluid of a temperature not lower than the plasticizing point of thethermoplastic resin tapes.

A split fibrous bundle, so-calledsplit yarn, is wellknown as a yarn-likethread manufactured previously from synthetic resin film. Theconventional split yarn is manufactured in'the following steps:

1. applying the synthetic resin tape to a high degree orientation insuch a manner as drawing in order to make it easily splittable, and

2. finely splitting the synthetic resin tape in a longitudinal directionby conventional chemical, physical o mechanical means.

Numerous proposals have been made in regard to the conventionalsplitting manner. However, any fibrous bundled thread manufactured bythe conventional manners are unsuitable for textile processing use,owing to the accompanying disadvantages as stated below:

1. undesirable thin and flat form, that is, unsatisfactory lowbulkiness,

2. easily producing of undesirable fluffs and disheveled fibers owing toa fact that the split fibers in the bundle are not bound to each other,

3. high frictional resistance in processing particularly, in a weavingor knitting process in which the fibrous bundle is frictionallycontacted with guides or other parts of a weaving machine or knittingmachine,

4. resulting of so-called paper-like fabrics which have unsatisfactorylow bulkiness, and

5. high thermal shrinkage.

in order to improve the processability and product performance of such asplit fibrous bundle, a twisted thread was manufacturedby a process oftwisting the split fibrous bundle. However, such a twisting process iseconomically undesirable owing to low efiiciency and expensiveprocessing costs. The product manufactured from the twisted splitfibrous bundle was less bulky than that from a non-twisted split fibrousbundle. Furthermore, when the products from the conventional splitfibrous bundle were subjected to a thermal treatment at hightemperature, the products resulted in large dimensional deformation andflattening owing to high thermal shrinkage thereof.

An object of the present invention is to provide a novel method formanufacturing highly efficient false twisted thread which has highprocessability for textile processing, such as weaving and knitting froma therb. eccentrically jetting a high pressure fluid of a temperaturenot lower than the plasticizing point of the thermoplastic resin tapeinto the thread forming means, by which can be produced an eddy streamof the fluid within the thread forming means,

c. bundling the fed tape to a cylindrical thread form by a falsetwisting action of the eddy stream,

(1. simultaneously thermosetting the bundled tape at the cylindricalthread form by a heating effect of the jetted fluid, and

e. delivering the resultant thread from the thread forming means.

The method of the present invention and the false twisted threadmanufactured by the method have the advantages as follows:

'1. the apparatus for this method is very simple in its construction,

2. the processing can be carried out at a high velocity, that is,several thousands meters/minute, these advantages (1) and (2) are basedon the fact that the desired spun yarn-like thread is obtained bypassing the thermoplastic resin tape through the eddy stream region ofthe high pressure fluid only,

3. the spun yarn-like thread has no fiuffs and disheveled fibers and isbundled in a cylindrical form, and

4. the spun yarn-like thread is low-thermal shrinkable.

Owing to the above-mentioned advantages, the false twisted threadmanufactured by the method of the present invention can be easilyapplied to the textile processing such as weaving and knitting andperformances such as bulkiness, handling-and appearance of the fabricsobtained from the false twisted thread resemble those of theconventional fabrics such as jute, ramie and linen fabrics. Therefore,the thread manufactured by the method of the present invention issufficiently usable for clothing, to which the conventional split yarncould not be applied, not to mention industrial use such as backingcloth for carpet, cord, rope,

twine, net, fishing net, and wall cloth.

The tape suitable for the method of the present invention may bemanufactured from any thermoplastic synthetic resin which is capable ofbeing formed into film form. The thermoplastic synthetic resins can beused, for example, polyolefine such as polyethylene and polypropylene.Polyvinyl chloride, polyacrylonitrile, polyamide such as nylon 6,polyester and polyvinyl alcohol are also suitable to this purpose.Preferably, polyethylene tape, polypropylene tape, andpolyethylene-polypropylene blended resin tape, particularly,polyethylene (5 to 40 percent by weight)- polypropylene (60 to percentby weight) blended resin tape are very suitable for the purpose of thepresent invention.

It is allowable to blend coloring matter such as pigment into thethermoplastic resin to obtain colored tape.

Further, an additional agent such as a foaming agent may be blended withthe thermoplastic resin in order to obtain an easily splittable tape.Furthermore, adhesives and plasticizers may be blended with thethermoplastic resin in order to obtain special tape.

The tape usable for the method of the present invention is prepared fromthe thermoplastic resin mentioned above by the conventional T-die methodor inflation method. The tape may be prepared by cutting FIG. 1 is aschematic view of an embodiment of an apparatus for carrying out themethod of the present invention,

FIG. 2 is a schematic view of another embodiment of an apparatuscontaining a splitting device for carrying out the method of the presentinvention,

FIG. 3 isa schematic view of an embodimentof an apparatus connected to asynthetic tape manufacturing apparatus for carrying out the method ofthe present invention,

FIGS. 4, 5 and 6 are front cross-sectional views of embodiments of anozzle device of the present invention, respectively,

FIGS. 7, 8 and 9 are side cross-sectional views of embodiments of anozzledevice of the present invention, respectively,

FIGS. l0A,l1A, 12A and 13A are cross-sectional views of embodiments ofthread prepared by the method of the present invention, respectively,and

FIGS. 10B, 11B, 12B and 13B are side views of the threads of FIGS; 10Ato 13A, respectively.

In FIG. 1, the tape 1 which is a starting material for the thread of thepresent invention is fed into a converting means comprising the nozzledevice 4 by way of a pair of feed rollers 2 and 2 through the guiderollers 9 and 9' at a specified velocity. The high temperature highpressure fluid 3 is eccentrically fed into the nozzle device 4 throughthe fluid feeding conduit 31 in order to form an eddy stream regionwithin the thread forming .tube 32. The tape 1 introduced into thethread forming tube 32 is false twisted and then bundled into acylindrical thread form by the actionof the eddy stream of the fluid andsimultaneously heat-set in this form by the heatof the fluid.

The tape 1 which is formed into the false twisted thread 5 in the threadforming tube 32 is discharged from the discharge outlet 34 by way of apair of delivering rollers 6 and 6 together with the fluid and taken upinto a cheese or cone 8 by the winding roller 7.

The starting tape 1 which has a high latent thermal shrinkage due toprevious drawing is relaxed in the nozzle device 4 by the action of thehigh temperature high pressure eddy stream of the fluid. The thermalshrinkage of the obtained thread therefore, is very small.

If the starting tape having a high degree of orientation is applied tothe method of the present invention, the starting tape can be split intofibrous form in the longitudinal direction by the action of the hightemperature, high pressure eddy stream of the fluid so as to form asplit fibrous bundle.

Further, a previously split starting tape may be used. FIG. 2 shows anembodiment of a thread manufacturing system from the split tape. Thestarting tape 1,

which is fed from a tape manufacturing process, is split into a finefibrous'form by way of the splitting cutter l 1 between a pair of feedrollers 10 and 10' and a pair of intermediate rollers 12 and 12. v

This previous splitting process may be carried out by way of theconventional splitting method and machine as follows:

l. the mechanical splitting by way of (a) the roller cutter, which has aplurality of knife edges on the peripheral surface thereof and (b) therotating pins and 2. physical splitting by utilization of (a) frictionalaction, (b) stretching action, (0) beating action and jetting force offluid.

The split tape 14 thus obtained is fed into the nozzle device 4 andconverted to false twisted thread by the same action as described above.

The splittable film may be manufactured by highly mono-axisdrawing ofthe thermoplastic resin film in the longitudinal direction, by which theorientation degree of the film may be improved.

In FIG. 3, a process in which the manufacturing process of the falsetwisted thread of the present invention continuously follows themanufacturing process of the starting tape is explained.

The thermoplastic resin is charged from the hopper 15 into the extruderl6, melted therewithin, extruded in a sheet form through the die 17. Theextruded resin is coagulated into a film form on the coolingroller l8.Successively, the film is delivered by the roller 20 from the coolingroller 18 through the guide roller 19 and fedto the film slitter 21disposed between the delivering rollers 20 and the snap rollers 22. Thefed film is slit by the film slitter 21 in a tape form. The slit tape isdrawn in the longitudinal direction between the first feeding rollers 23and the first delivery rollers 24 while the tape is heated in the firstheating device 25 disposed between these rollers.

The drawn tape is fed into the second heating device 29 through the snaprollers 26 and the second feed rollers 27 in order to subject the tapeto a heat treatment at a fixed length of the tape.

The heat treated tape is delivered from the heating device 29 by thedelivery rollers 28. If necessary, the tape is slit by the splittingroller 1 1, the tape or the split tape is fed into the nozzle device 4through the third feeding rollers 12 and converted into a false twistedthread in the same manner as FIG. 1.

The nozzle device or converting means 4 will be explained in detailhereinafter. Any nozzle device as shown in FIGS. 4-to 9 isvprovided'with a cylindrical thread forming tube 32, a funnel-shapedsurface or tape passage 30, a fluid passage 35 formed in the form of anannular space between the outside surface of the tape passage and theinside surface of the thread forming tube 32 and at least a fluidconduit 31. FIG. 4 shows an embodiment of the nozzle device having onlyone fluid conduit 31. FIGS. 5 and 6 showembodiments of the nozzledevices having two and four fluid conduits, respectively. Every fluidconduit 31 is arranged in an eccentric tangential position with respectto the fluid passage 35. The fluid is eccentrically jetted into thefluid passage 35 through the fluid conduit 31 to form a fluid vortex andfurther jetted into the thread forming tube 32 under a high pressurejetted condition. The high pressure fluid thus produces an eddy streamor vortex stream in which the fluid is spiraling within the threadforming tube. In FIG. 7, only a fluid conduit 31 is connected fluidly tothe fluid passage 35. In FIG. 8, two fluid conduits 31 and 31 areconnected fluidly to the fluid passage 35 in a manner as shown in thedrawing. The high temperature high bressure fluid may be jetted into thethread forming tube 32 through both fluid conduits 31 and 31', but inanother case, the high temperature high pressure fluid may be jettedthrough any one of the fluid conduits 31 and 31 and a room temperaturefluid is jetted through another conduit. In case two or more nozzledevices are arranged in series, the high temperature high pressure fluidmust be jetted into at least one of the nozzle devices in order toachieve the purpose of the present invention.

The nozzle device 4 shown in FIG. 9 is provided with two improvements.That is, the supplementary heater 33 is disposed on the peripheraloutside surface of the thread forming tube 32 in order to reinforce theheating effect of the fluid, further, the spiral fluid passage 36 isformed in the space 35 connecting the fluid conduit 31 to the threadforming tube 32 in order to reinforce the eddys stream formation of thefluid. The fluid jetted through the fluid conduit 31 produces areinforced eddy stream during passing through the spiral fluid passage36. The tape fed through the tape passage 30, therefore is convertedinto a desirable thread form due to the action of the reinforced eddystream of the fluid and effect of the reinforced heating. Ratio offeeding velocity of the starting tape with respect todelivering-velocity of the resultant thread is important data for themethod in accordance with the present invention. Namely, in FIGS. 1 and2, the ratio of peripheral velocity of the feeding rollers 2 and 2' withrespect to peripheral velocity of the delivering rollers 6 and 6 closelyrelates to the configuration of the resultant thread. The velocity ratiomust be suitably snecified according to the kind of starting tape,treatingvelocity of the tape,.kind of fluid to be jetted, andtemperature thereof. Usually, the delivering velocity of the resultantthread may be adjusted in a range of 80. to 110 percent, preferably 90to 100 percent of the feeding velocity of the starting tape. That is, itis preferable that the feeding velocity of the starting tape exceed thedelivering velocity of the resultant thread in a range of 0 to 10percent. Because, the starting tape shrinks in the nozzle device by theheating effect of the fluid owing to its high thermal shrinking propertywhich is caused by the drawing process in the tape manufacturing. Thehigh thermal shrinkage of the starting tape is effective for forming thecylindrical tape bundle. The resultant thread, which has a low thermalshrinkage owing to the thermal shrinking in the thread forming process,is not required to have any heat treatment process, which is requiredfor the conventional split yarn. Further, the

above-mentioned overfeed of the starting tape is effective for promotingthe false twisting effect of the fed tape by ensuing the splittingeffect the fluid. In the special case, the resultant thread is deliveredfrom the nozzle device, being stretched at a delivering velocity higherthan the feeding velocity, the resultant thread is compactly bundled ina cylindrical form and, thus, has a stable structure by allowing thetemperature of the fluid to rise close to the melting point of thestarting tape.

. ing tape with the eddy stream of high temperature fluid is a novelmanner which can not be found in the conventional film yarnmanufacturing. Air, steam or superheated steam, which have been heatedto a plasticizing temperature or higher of the starting tape, may beused as the jetting fluid. Furthermore, plasticizers, solvents, swellingagents or adhesives for the starting tape may be mixed into the jettingfluid. The temperature and pressure of the jetting fluid may be selectedappropriately in accordance with the kind of starting tape, treatingvelocity and object of manufacture. For example, in case polyolefineresin tape is used for the method, it is desirable to treat thepolyolefine resin tape with superheated steam at a high treatingvelocity of to 2,000 m/min. Pressure of the jetted fluid may be selectedfrom a range between 0.5 to 10 kg/cm but the range of 2-4 kg/cm isparticularly preferable.

The thread, just after treatment by the high temperature eddy stream offluid, has a considerably high temperature. Thus, the high temperaturethread can be modified easily to a thread of which the outside surfaceis uniformly fused by passing the thread through a die heated to athread melting point or higher, or to a thread of which the outsidesurface has various rugged patterns by passing the thread through a pairof high temperature embossing rollers.

The spun yam-like thread manufactured by the method of the presentinvention may be provided with various forms, configurations andcharacteristics. Some examples of the thread are shown in FIGS. 10A to138. The thread, as shown in FIGS. 10A and 10B is manufactured in acondition in which a temperature of the jetted fluid is relatively lowand an overfeed percentage for the starting tape is approximately 5"nercent. The thread by the false twisting action of the jetted fluid inthe nozzle device, is more stable for thermal shrinking and deformingthan the conventional split yarn.

The thread, as shown in FIGS. 11A AND 118, is manufactured in acondition which a jetted fluid temperature is higher than that of FIGS.10A and 108. This thread is more bulky than the thread of FIGS. 10A and108. The split fibers 40 in the thread of FIGS. 11A and 11B arecylindrically bundled in a partially entangled condition with adjacentfibers by action of the eddy streamof fluid and deformed into an unevenshape by the effect of high temperature fluid in order to impartbulkiness. Furthermore, since all fibers in the thread are thermallytreated by the high temperature fluid so that each split fiberpositioned at an outside surface part of the thread is partially fusedand bound with adjacent fibers, the structure of the resultant thread isvery stable, and thus, the resultant thread can be satisfactorilyprocessed for weaving and knitting, the same as or more easily than thatof the conventional twisted spun yarn. Density of the split fibers in acrosssection in the resultant thread is considerably higher than that ofthe conventional split yarn and it is easy to make the density resembleconventional spun yarn.

The knitted or woven fabrics manufactured from the spun yarnelike threadhas a desirable handling closely resembling that of the conventionalspun yarn fabric.

The thread, as shown in FIGS. 12A and 12B, is manufactured in acondition where a percentage of the overfeed is l to 2 percent. Thisthread has a similar performance as the conventional hard twisted yarn,with the exception of relatively low bulkiness due to a densely packedstructure.

The thread, as shown in FIGS. 13A and 13B, is manufactured under acondition where the temperature of the jetted fluid is higher than thatof FIGS. 12A and 12B and the delivering velocity of the resultant threadis to percent higher than the feeding velocity of the starting tape inorder to stretch the starting tape. In this case, the resultant threadis bundled tightly into a cylindrical form but the surface and thecontacting parts of the tapeare fused and bound into a wire-form. Thus,the structure of the resultant thread is very stable.

The spun yarn-like threads manufactured by the method of the presentinvention can be satisfactorily utilized as weaving or knitting yarn forgeneral purposes. Particularly, in case high strength thread isrequired, for example, in the field of industrial use, it is capable ofreinforcing the strength of the thread by further true twisting and incase very low thermal shrinkage thread is required, it is capable oflowering the thermal shrinkage of the thread by further thermosettingthe thread in a fixed length condition at a temperature suitable to thethermal property of synthetic resin which composes the thread.

The starting tape may be used together with one or more of the same ordifferent tape of tapes in a doubled condition. a

The following examples illustrate various methods of carrying out thepresent invention, but it is to be understood that these examples aregiven by way of illustration and not of limitation. v

EXAMPLE 1 Uniaxially drawn polypropylene tape of 1,000 denier fineness,15.7 microns thickness and 6.5 mm width was treated under the followingconditions with the system shown in FIG. 1 vto manufacture a spunyarn-like thread.

I. Feeding velocity of tape: 2,000 m/min 2. Delivering velocity ofthread: 1,980 m/min 3. Nozzle device:

A device as shown in FIG. 9 was applied.

The device contained a fluid conduit. 4. Fluid:

Superheated steam of a temperature of 300C and a gauge pressure of 3.0kg/cm was used.

I The properties of the resultant thread and the starting tape are shownin Table l.

thread Note: I Thermal shrinkage is measured in a manner where the tapeor thregd is treated by dry air of 120C for l0 minutes in the freelength con ition.

EXAMPLE 2 A polyethylene tape of 1,800 denier fineness and 22 micronsaverage thickness which was manufactured througha uniaxial drawingprocess and having a corrugated cross-section, was treated in the systemas shown in FIG. 1 under the following conditions.

1. Feeding velocity of tape: 2,000 m/min 2. Delivering velocity ofthread: 1,900 m/min 3. Nozzle device:

A device as shown in FIG. 7 was applied.

The device contained four fluid conduits as shown in FIG. 6. I

Fluid:

High temperature air of 200C temperature and 2.5 kg/cm gauge pressurewas used.

The properties of the .resultant thread and the start ing tape are shownin table 2.

TABLE'Z Breaking Thermal Items Tenacity (g) Elongation Shrinkage Gk)Starting v 3,395 11.58 6.3 tape Resultant 3,386 5.80 l.6 thread Note: 2Thermal shrinkage was measured in a manner that the tapeor thread istreated in hot water of C for 10 minutes in the free length con ition.

The resultant thread had the structure and appearance as indicated inFIG. 11, and was suitable for use as fringes and backing cloth ofcarpet.

EXAMPLE 3 A composite polypropylene tape of 1,000 denier fineness and 20microns thickness was prepared from a film manufactured bymelt-extruding two mutually adherent polypropylene polymers havingdifferent polymerization degree, from each other through the same dieand had two polypropylene layers arranged face to face along the lengthof the tape and adhered to each other.

The composite tape was provisionally split into a split fibrous bundleand formed into a thread in the system shown in FIG; 1 under the sameconditions as stated in example i.

The properties of the resultant thread and the starting fibrous bundleare indicated in table 3.

Note: 3 Thermal shrinkage was measured in the same manner as stated InExample I. I

The resultant thread had-a curled appearance as shown in FIG. 11 due todifference of thermal shrinkages of componental polypropylene layers andhandling was similar to conventional spun yarn.

EXAMPLE 4 A foamed polyethylene tape of 3,000 denier fineness and 50microns thickness prepared from a film manufactured by melt-extruding amixture of 99.7 parts of polyethylene resin and 0.3 parts ofazodicarbonamide as a foaming agent and drawing in the longitudinaldirection of the film. The prepared tape was subjected to thread formingof the system of FIG. 2 under the following conditions.

l. Feeding velocity of tape: 500 m/min 2. Peripheral velocity of cuttingroller: 800 m/min 3. Peripheral velocity of intermediate roller: 510m/min 4. Delivering velocity of thread: 500 m/min 5. Nozzle device:

A device as shown in FIG. 8 was applied.

The device contained five fluid conduits.

6. Fluid: Superheated steam of temperature 200C and gauge pressure 2.0kg/cm was used.

The properties of the resultant thread and the starting tape were asshown in the following table 4.

TABLE 4 Breaking Thermal 7 Item Tenacity (g) Elongation Shrinkage ('k)Starting ll,800 12.3 8.6 tape Resultant 12,240 8.1 3.3 thread Note: "4Thermal shrinkage was measured in the same manner as stated in Example2.

The resultant thread had a spun yarn-like structure and an appearance asshown in FIG. 12 and was suitable for use as a ground yarn forWiltoncarpet.

EXAMPLE A colored film was prepared by the manufacturing system as shownin FIG. 3. In the system, 78.5 percent by weight of stereo-specificpolypropylene of melt index 5.0, 20 percent by weight of polyethylene ofmelt index 2.0 and 1.5 percent by weight of yellow pigment DP-6044(which was obtained from Dainippon Ink Manufacturing, Ltd., Japan) weremixed. The mixture 10 was melt-extruded through a T-shaped die of anextruder which has a melting cylinder of mm inner diameter. Theresultant film was of 60 microns thickness. The resultant film wassubjected to a cutting off to a width of 20 mm along a longitudinaldirection, drawing at a drawing ratio of 8.5 and heat-setting by way ofan infrared ray heat-setter in a fixed length in order to prepare astarting tape having a fineness of 1,000 deniers and high orientation.

g The starting tape was subjected to the thread forming process underthe following condition.

1. Feeding velocity of tape: 140 m/min 2. Delivering velocity of thread:134 m/min 3 Nozzle device:

A device as shown in FIG. 7 was applied. The device has a fluid conduitas shown in FIG.

4. Fluid:

Superheated steam of a temperature of 200C and a gauge pressure 2.5kg/cm'.

The resultant thread was subjected to weaving for a backing cloth forcarpet. The workability of the resultant thread for the weaving processwas as shown together with three comparisons in the following table.

TABLE 5 Compar- Compar- Compar- Example ison ison ison Example exampleexample example Items 5 1 2 3 Shrinkage at 120C 3.5 0.3 5.3 4.4 Workefficiency in the preparation process for weaving and weav- Excel-Stand- Good Slightly ing process for backlent ard poor 7 ing cloth'SWork efficiency in the tufting process for Excel- Stand- Rather Slightlycarpet"5 lent ard poor poor Adhesive strength of the resultant back-1890 4245 605 663 ing cloth (g)'6 Fixing force of the resultant backingck;th7for pile yarn 2230 2320 I490 1840 (a Shrinkage of the resultantbacking cloth in curing 1.35 1.06 1.60 1.60 process8 Note: "5 Workel'ficiency in the preparation process for weaving, weaving process forbacking cloth and tulting process for carpet manufacture was evaluatedon the basis of the jute yarn.

"6 Adhesive strength of the resultant backing cloth was measured in thatlatex of 30% concentration was coated on the surface of a 5 cm X 5 cmtest piece of backing cloth, a noncoated test piece was attached ontothe coated test piece. the attached pieces were dried in the atmosphereand subjected to heat-treatment at C for 20 minutes in order to firm theadhesion and the force required for feeling the adhered test pieces wasmeasured by way of a Schopper-type tensile strength tester.

"'7 Fixing force of the resultant backing cloth for pile yarn of carpetwas measured in that a pile yarn was prepared by doubling two finishedpolypropylene multifilament yarns of 1800 dinier/ filaments. The

pile yarn was subjected to tufting for the resultant backing cloth inorder to prepare a carpet, a test piece of 5 cm x cm was obtained fromthe resultant carpet and latex of 50% concentration was coated on a backsurface of the test piece, dried in the atmosphere and heattreated at100C for 20 minutes. The force required for pulling out the pile yamfrom the test piece was measured.

*8 Shrinkage of the resultant backing cloth in the curing process wasmeasured in that the backing cloth was heated at I30" C for 15 minutesin a heating oven and allowed to cool to room temperature. The

. average value of shrinkage in a warp and weft direction of the curedbacking cloth was measured. 1

v In table 5, it could be seen that the backing cloth prepared from thethread of the present example 5 had better adhesiveness, fixing forcefor pile yarn and working efficiency and lower thermal shrinkage thanthe conventional split yarn and tape yarn. Thethread of the presentexample 5, also had better working efficiencies for a preparing process,weaving process and tufting process than those of the jute yarn.

; EXAMPLE 6 An acrylic tape was prepared from acrylonitrile-vinylacetate (93 7 by weight) copolymer resin. The intrinsic viscosity'of thecopolymer was 1.62 in dimethyl formamide at 25C. The copolymer wasdissolved into dimethyl form'amide'in a concentration of 23.0 percent byweight. The solution was extruded into a polyethyleneglycol bath of 80Cthrough a nozzle of 1. Feeding velocity of tape: 200 m/min 2. Deliveringvelocity of thread: l80 m/min 3. Nozzle device: I

A device as shown in FIG. 7-was applied.

The device had a fluid passage. 4. Fluid: v

Superheated steam of 350C and a gauge pressur e of 2 kg/cm was fed.

The resultant thread, which was split into a fibrous bundle andsimultaneously thermoset in a cylindrical form, had a tenacity of 1,430g and a breaking elongation of 130 percent. The thread was suitable asyarn for knitting sweaters.

EXAMPLE 7 Two polypropylene tapes which are the same as that of example1, were subjected to a thread formation process under the same conditionas stated in example 1. The tapes were doubled and fed into the nozzlevdevice. The resultant thread in which the componental two tapes werefalse twisted and partially melt-bonded with each other so as to form athread, was further subjected to a heat-setting treatment by passing thethread through a heating air box of 2 mlength and 200C temperature at avelocity of 2,000 m/min.

The final resultant thread was thermally stabilized by the heat-settingtreatmentand is useful for manufacturing rope, cord, twine and net.

Lll

.2... EXAMPLE 8 The false twisted polypropylene thread prepared by thesame process as stated in example 1, was further subjected to a hightemperature heat treatment by passing the thread through a heating boxof 2m length and 300C temperature at a velocity of 2,000 m/min. Theresultant thread, the surface of which was partially molten, has a juteyarn-like appearance and hand feeling and usable for manufacturing rope,cord and fishing net.

What we claim is:

1. A method for manufacturing false twisted thermoplastic resin threadscomprising: feeding a thermoplastic resin tape into a cylindrical threadforming means, eccentrically jetting a high pressure fluid having atemperature not lower than the plasticizing temperature of saidthermoplastic resin tape into said thread forming means to forman eddystream of said fluid within said thread forming means effective to falsetwist andsplit the fed-tape by a twisting action of said eddy stream toconvert the resin tape to a cylindrical bundled thread form,simultaneously thermo-setting said cylindrical bundled thread form bythe heating effect of said fluid, and delivering said resultant threadfrom said thread forming means.

2. A method asset forth in claim 1, in which said fluid is air. i

3. A method as set forth in claim 2, in which said polyolefine resintape is a polypropylene tape.

4. A method as set forth in claim 2, in which said polyolefine resintape is a polyethylene resin tape.

5. A method as set forth in claim 2, in which said polyolefine resintape is a mixed resin tape consisting of polypropylene resin andpolyethylene resin.

6. A method as set forth in claim 5, said mixed resin tape consists of60 to percent polypropylene resin and 5 to 40 percent polyethyleneresin.

7. A method as set forth in claim 1, in which said fluid is steam.

8. A method as set forth in claim 7, in which said steam is superheatedsteam.

9. A method as'set forth in claim 1, in which said thermoplastic resintape is a polyolefine resin tape.

10. A method as set forth in claim 1, said thermoplastic resin tape isan acrylic resin tape.

11. A method as set forth in claim 1, in which said thermoplastic tapeis a highly oriented thermoplastic resin tape.

12. A method as set forth in claim 1, in which a pressure of said fluidis 0.5 to 10 kglcm 13. A method as set forth in claim 12, in which saidpressure of said fluid is 2 to 4 kg/cm.

14. A method as set forth in claim 1, in which said resultant thread isdelivered at a delivering velocity of 80 to percent with respect to afeeding velocity of ,two thermoplastic resin tapes are fed into saidcylindrical thread forming means in a parallel tape form.

18. A method as set forth in claim 1, in which said thermoplastic resintape which is just manufactured through a tape manufacturing means issuccessively fed into said cylindrical thread forming means.

19. A method as set forth in claim 1, further comprising thermo-treatingsaid resultant thread at a desired temperature.

20. A method as set forth in claim 19, in which said thermo-treatingtemperature is at least a melting point of said thermoplastic resintape.

21. A method for manufacturing resin threads comprising: providing aplasticizable resin tape to be formed into a thread; longitudinallyadvancing said resin tape through a cylindrical zone; and contacting theadvancing resin tape within said cylindrical zone with a fluid vortexhaving sufficient temperature and pressure to effect splitting andbundling of the resin tape into a cylindrical thread accompanied byheatsetting of the cylindrical thread by the heat energy of the fluidvortex.

22. A method according to claim 21; wherein said to Kg/cm.

25. A method according to claim 21; wherein said advancing stepcomprised longitudinally advancing said resin tape through saidcylindrical zone from an entrance end thereof to an exit end thereof andwherein the advancing rate of the bundled resin tape at said exit end isto that of the resin tape at said entrance end.

1. A method for manufacturing false twisted thermoplastic resin threadscomprising: feeding a thermoplastic resin tape into a cylindrical threadforming means, eccentrically jetting a high pressure fluid having atemperature not lower than the plasticizing temperature of saidthermoplastic resin tape into said thread forming means to form an eddystream of said fluid within said thread forming means effective to falsetwist and split the fed tape by a twisting action of said eddy stream toconvert the resin tape to a cylindrical bundled thread form,simultaneously thermo-setting said cylindrical bundled thread form bythe heating effect of said fluid, and delivering said resultant threadfrom said thread forming means.
 2. A method as set forth in claim 1, inwhich said fluid is air.
 3. A method as set forth in claim 2, in whichsaid polyolefine resin tape is a polypropylene tape.
 4. A method as setforth in claim 2, in which said polyolefine resin tape is a polyethyleneresin tape.
 5. A method as set forth in claim 2, in which saidpolyolefine resin tape is a mixed resin tape consisting of polypropyleneresin and polyethylene resin.
 6. A method as set forth in claim 5, saidmixed resin tape consists of 60 to 95 percent polypropylene resin and 5to 40 percent polyethylene resin.
 7. A method as set forth in claim 1,in which said fluid is steam.
 8. A method as set forth in claim 7, inwhich said steam is superheated steam.
 9. A method as set forth in claim1, in which said thermoplastic resin tape is a polyolefine resin tape.10. A method as set forth in claim 1, said thermoplastic resin tape isan acrylic resin tape.
 11. A method as set forth in claim 1, in whichsaid thermoplastic tape is a highly oriented thermoplastic resin tape.12. A method as set forth in claim 1, in which a pressure of said fluidis 0.5 to 10 kg/cm2.
 13. A method as set forth in claim 12, in whichsaid pressure of said fluid is 2 to 4 kg/cm2.
 14. A method as set forthin claim 1, in which said resultant thread is delivered at a deliveringvelocity of 80 to 110 percent with respect to a feeding velocity of saidthermoplastic resin tape.
 15. A method as set forth in claim 14, inwhich said delivering velocity is 90 to 100 percent of said feedingvelocity.
 16. A method as set forth in claim 1, further comprisingheating said fluid jetted into said thread forming means to a desiredtemperature.
 17. A method as set forth in claim 1, in which at least twothermoplastic resin tapes are fed into said cylindrical thread formingmeans in a parallel tape form.
 18. A method as set forth in claim 1, inwhich said thermoplastic resin tape which is just manufactured through atape manufacturing means is successively fed into said cylindricalthread forming means.
 19. A method as set forth in claim 1, furthercomprising thermo-treating said resultant thread at a desiredtemperature.
 20. A method as set forth in claim 19, in which saidthermo-treating temperature is at least a melting point of saidthermoplastic resin tape.
 21. A method for manufacturing resin threadscomprising: providing a plasticizable resin tape to be formed into athread; longitudinally advancing said resin tape through a cylindricalzone; and contacting the advancing resin tape within said cylindricalzone with a fluid vortex having sufficient temperature and pressure toeffect splitting and bundling of the resin tape into a cylindricalthread accompanied by heat-setting of the cylindrical thread by the heatenergy of the fluid vortex.
 22. A method according to claim 21; whereinsaid contacting step comprises contacting the advancing resin tape at anupstream portion of said cylindrical zone sufficiently remote from thedownstream end thereof to ensure that the bundled resin tape is heatedenough by the fluid making-up said fluid vortex to effectively heat-setthe bundled resin tape in its cylindrical thread configuration.
 23. Amethod according to claim 21; wherein said fluid vortex has atemperature not lower than the plasticizing temperature of saidplasticizable resin tape.
 24. A method according to claim 21; whereinsaid fluid vortex has a pressure within the range of from 0.5 to 10Kg/cm2.
 25. A method according to claim 21; wherein said advancing stepcomprised longitudinally advancing said resin tape through saidcylindrical zone from an entrance end thereof to an exit end thereof andwherein the advancing rate of the bundled resin tape at said exit end is80 to 110% that of the resin tape at said entrance end.